This invention relates to a process for producing coated europium acrivated strontium borate phosphors. More particularly it relates to a process for producing europium activated strontium borate phosphors coated with a strontium containing coating.
A phenomenon observed during the lamp lehring process with eropium activated stontium borate, using both the organic and water based binder systems, is the formation of brown phosphor discoloration and glazing of the glass. This phenomenon is associated with the surface activity of the phosphor where it is exposed during the lehring phase of lamp manufacturing. The brown discoloration appears to be associated with carbon being trapped on the phosphor surface.
Elimination of the boric acid and preventing an interaction of the phosphor with the binder would be desirable.